1. Field of the Invention
The present invention relates generally to a camera having an automatic flash function and method. More particularly, the present invention relates to a camera having an automatic flash function in accordance with an amount of charge voltage.
2. Description of the Related Art
Generally, the quality of a photograph depends mainly on an ambient brightness around an object when taking a photograph. Therefore, a problem associated with ambient brightness around the object, especially at night or indoors, at the time of photographing has been solved by voluntarily emitting a flash for a predetermined time to have almost the same effect as sunlight. Accordingly, the flash, which has a large amount of light and a high color temperature, compensates for the inadequate brightness when taking a photograph at night or indoors.
For carrying out the above operation, the camera should include a strobe and such strobe should emit a transient flash concurrently with the operation of a shutter. To emit the transient flash, a Xenon lamp capable of emitting the flash is used. Conventionally, since the camera is portable, a light dry battery is used for power, but the Xenon lamp requires a much higher voltage for power. A transformer is used which increases the voltage level of the dry battery to output the higher voltage power. Accordingly, the dry battery, the transformer and the Xenon lamp are basic elements in a strobe circuit, and are properly used with variations in accordance with required designs. Such a strobe device is designed to operate concurrently with the operation of the shutter to emit a predetermined amount of flash.
"Strobe Control Apparatus", U.S. Pat. No. 5,016,138 issued on May 14, 1991 discloses a conventional technique as follows. The technique does not charge the strobe if a set time to prevent the charging does not pass by after the charging is completed to prevent incorrect operations of devices such as a transistor and the transformer of the strobe due to heat generated by frequent emissions of the strobe if the charging time and the charged voltage of the strobe are selected in accordance with the operation condition of the camera, or stops the charging if the charging time passes by, even though the strobe is not fully charged.
However, the above "Strobe Control Apparatus" has a disadvantage because the user cannot capture a transient, spontaneous image of an object when the user wishes to take a photograph quickly, taking into consideration the distance from the object and an F number, since strobe charging is controlled in accordance with the charging time and the charged voltage of the strobe.
The conventional camera has other disadvantages in that the user will miss the opportunity to photograph the transient, spontaneous image since the photograph is possible only when the strobe is fully charged even though the release switch is activated. Accordingly, the user cannot obtain a photograph with suitable exposure since the strobe emits a predetermined amount of flash, regardless of the distance from the object.